Understanding grain virtual water flux dynamics and drivers from a socio-ecohydrological perspective: A case study of landlocked developing countries of Africa

The virtual water (VW) approach offers a crucial heuristic tool to analyze water and food security by considering the water embedded in grain during the whole production process. African landlocked developing countries (LLDCs) continually suffer from an escalating food crisis and water resources and socioeconomic policy and water conservation strategy derived from the water-food nexus of virtual water trade (VWT) systems and resources may be the solution. Using a trade gravity model and multilateral data, this study evaluated grain VW flux patterns and 11 main drivers of VWT between 16 African LLDCs and their partners. Besides, the feedback path of VW flows corresponding to the socio-ecohydrological variability was studied using the impulse response function. The findings revealed that net virtual water import (VWI) varied across all 16 African LLDCs, ranging from 1.67 Bm³ to 10.28 Bm³ during 2000 and 2020, with an estimated yearly grain VWI of 105.61 Bm³. Green, blue, and grey water accounted for about 79.3%, 14.7%, and 5.98% of the total grain VWI, respectively. Ethiopia had the highest grain VWI among the African LLDCs. Grain VWI fluxes were significantly and positively driven by population growth and per capita GDP, which were expected to continue in the future. It was concluded that the quantitative analysis of grain VWT patterns and driving forces using the VW theory for LLDCs can be instrumental for guiding the socioeconomic policy and water conservation strategy. To effectively achieve sustainable water security and grain production, earmarked future VW strategy is required. Decision-makers should incorporate rational VW strategies and socio-ecohydrological factors into the monitoring system from a multidisciplinary perspective.